Screw



Jan. 3, 1939.

J. F. FlEG SCREW Filed Oct. 8, 1957 Q FQQ Pat nted Jan. 3,- 1939 Joseph F. Fieg, La Grange, 111., assignor to United Screw and Bolt Corporation, Chicago, v 111., a corporation of Ohio Application October 8, 1937, Serial No. 167,893

11 Claims.

This, invention relates in general to screws and particularly to certain structural features which are advantageous in the use of the screws. While the invention is herein illustrated as embodied in a machine screw, it should be appreciated that the principles of the invention are equally applicable to wood screws, set screws, and, in fact, to screws of any kind whether hardened or not and whether intended to be driven into place with a hand operated screw driver or a power driven tool.

In my prior Patent No. 1,894,034, issued January 10, 1933, I disclosed a screw possessing certain advantages therein set forth over ordinary slotted head screws commonly in use.

vention is an improvement upon the structure disclosed in said patent and embodies not only all of the advantageous features of the screw of that patent but also additional advantageous features which are highly desirable in many types of screws and for many purposes.

A screw of the character to which this invention relates has a recess or socket adapted for the reception of a tool in the form ofa screw driver by which the screw is rotated and thereby driven into place. The socket centers the tool with respect to the screw and prevents the tool from slipping out of place as it frequently does with ordinary slotted head screws. Screws of the character with which my invention is concerned are very commonly driven into place with a power operated screw driver so constructed that when the end of the screw driver blade is pressed against the end of the screw a clutch is thrown in connecting the blade with the motor so that the blade immediately begins to rotate. Often the rotation of the blade is begun before its end has really entered the socket of the screw,

and in such instances where the end of theblade is resting against the surrounding walls of the socket when rotation of the blade is started, the blade is as apt to slip laterally off from the screw as it is to slip inwardly into the socket.

One of the purposes of my present invention is to provide a screw which will facilitate the entrance of the tool blade into the socket, particularly when rotation of the blade is initiated.

Another purpose of the invention is to provide a screw driver blade which in conjunction with my improved screw head will further facilitate and insure the entrance of the blade into the screw head socket.

In modern practice screws are frequently employed in locations where it is very difiicult to 55 place and start them, particularly screws of the My present in thread forming machine screw type having a blunt entering end. Not infrequently, the location where the screw is to be driven is so inaccessible that the mechanic or user is unable to hold the screw in position with'one hand while 5 he manipulates the drivingtool with the other. If, however, the screw were attached to and carried by the end of the tool, the screw could be easily guided and started.

Another and very important feature of my 10 present invention is the provision of a screw so constructed that it may be very readily and securely attached to the screw driver blade so that it may be positioned and started by merely guiding the driving tool and without otherwise 15 positioning or guiding the screw.

Other objects and many of the inherent features of my present invention will be readily appreciated as the same becomes better understood by reference to the following description when considered in connection with the accompanying drawing. I

Referring to the drawing,

Fig. 1 is a plan view of my novel screw showing in cross section a screw driver blade in driving position in the socket of the head;

Fig. 2 is a similar view showing the screw driver blade in aposition with respect to the screw in which the screw is frictionally locked to the blade;

Fig. 3 is a sectional view on the line 3-3 of Fig. 1 but showing the screw driver blade in full lines as withdrawn'from the socket and in dotted lines asentering the socket; and

Fig. .4 is a sectional view on the line 44 of Fig. 2 showing the screw driver blade withdrawn from the socket and with its fiat face presented to view.

I Referring now to the drawing more in detail, reference character 5 indicates generally the 40 body or shank of a screw threaded, as shown, and provided with a head 6. The body may be I either of the machine screw type, as illustrated,

or of the wood screw type and may be provided with threads of any suitable character. Likewise, the head 6 may be either of the flat type illustrated, or of the round or any other preferred type, as my invention is equally applicable to screws of various types including any preferred type of headless screw or a screw provided with a head.

In the embodiment shown, the head of the screw is provided with an axially disposed recess or socket, indicated generally by reference character i which, if preferred, may be of uniform depth but preferably is of maximum depth at its center, as indicated by reference character 8. The socket is provided with oppositely disposed abutments or teeth 9 each providing an abutment face I I in position to be engaged by the flat face of a tool such for instance as a screw driver blade I2 positioned diametrally in the socket and rotated in a clockwise direction viewing Figs. 1 and 2 into the position shown in Fig. 1 in which further rotation of the blade will rotate the screw for driving purposes. In this respect, the abutment teeth 9 are similar to the corresponding structure of my prior patent to which reference has been made.

For the purpose of providing a frictional attachment of the screw to the tool blade in order that the screw may be carried by the blade and thereby positioned for driving in inaccessible locations, the circumferential walls of the socket 1 between the abutment teeth 9 are formed eccentric to the axis of the screw and socket. Viewing Figs. 1 and 2, it will be observed that the points II at the bases of the abutment faces II of the teeth 9 are more remote from the axis of the socket than the points I4 at the bases of the other faces of the teeth. In other words, the circumferential walls I5 of the socket or at least a portion thereof between the teeth are formed on progressively shorter radii at progressively increasing distances from the abutment faces II of the teeth. The diametral dimension of the socket is therefore greater on a diameter paralleling the faces than it is on a diameter paralleling the other faces of the teeth.

The tool blade I2 is dimensioned so that it may be readily introduced and withdrawn from the socket when disposed diametrally of the slot in approximation to the position which it assumes in Fig. 1. From this figure it will be observed that considerable clearance is afforded between the edges of the blade and the opposed walls of the socket. The tool may therefore-be inserted and removed without resistance when disposed substantially in the position shown in Fig. 1.

- Should it bedesirable to attach the screw to the-tool for placement and guiding purposes or otherwise, such'a'ttachment is readily effected by simplyjtur'ning,the-tool blade in a reverse or counterclockwise direction in the socket from the position shown in Fig. Ito-that shown in Fig. 2 from which it' will be observed-thatthe edges ofthe blade have'bythis movement been brought into frictional holding engagement with'and between the walls I5 so that the screwis securely locked to the blade and may be carried thereby to any desired'loca-tion which might otherwise be inaccessible for the starting. of the screw. When the screw attached to the blade has been properly located, it may be' driven in the usual manner, since a partial clockwise rotation-of the tool blade will release the friction hold and-bring it inabutting ,relation. with the abutment surfaces n .b w i d iv ng ,rotation is: dliverd mg Screwfromthe b1 d e To facilitate the: introduction or the m1. blade into the socket,'the exposed-upper ends Iiof th'eteethlarefinclineddownwardly andiinwardly;

as best shown in F-lg. 4, insteadjof being p'arallel with the ,endiface. of the screw, as l inmy' -prior patent. These inclined tooth. ends causegthe-tooi 1 blade to readily "slideinto the-f'socketjthereby obviating manylate'ral -slippa'ges ofthe tool of! the head of the screw which have heretofore occurred when an 'improp'erly'placed' tool began to rotate under power. These inclined-surfaces will obviously facilitate the introduction of a hand operated screw driver into the socket in the same manner that they do a power-operated tool.

An ordinary screw driver either hand or power operated or any fiat type or suitably shaped polygonal tool may be employed with screws embodying my invention, the only requirement being that the tool blade be sufllciently narrow to enter the socket in its largest diametral dimensions and sufliciently wide to engage the eccentric peripheral walls of the socket when reversely rotated if attachment of the screw to the blade is desired. An additional feature of my invention, however, which enables the introduction of the tool blade into the socket with even greater facility resides in the design of a tool blade which, as illustrated in Figs. 3 and 4, is bluntly pointed instead of having a straight and perpendicular to the axis of the tool, as is customary. My novel blade has tapered end walls I1 and I8 terminating at their intersection in a sharp or blunt point I9, and preferably also the side faces are tapered, as indicated at 2I toward the point I8.

In the application of this tool to a screw of my design, if the point I9 is positioned anywhere within the periphery of the socket, whether upon the exposed faces of the teeth 9 or elsewhere, en'dwise pressure exerted upon the tool will cause it to slide immediately toward the center of the socket and become properly positioned therein. An exempliiication of this action is illustrated by the dotted line position of the tool in Fig. 3.

It is believed that from the foregoing the principles of my invention and its attendant advantages will be understood and appreciated without further elaboration. The structural details, however, illustrated and described are obviously capable of considerable modification and variation without departing from the essence of the invention as defined in the following claims.

I claim:

1. A screw having a socket provided with teeth spaced apart to accommodate between them a tool extending diametrally of the socket, said teeth afiording abutment surfaces for said tool through which rotary movements of the tool in one direction are imparted to the screw, the exposed ends of said teeth being inclined to facilitate entrance of the tool into said socket and the diametral distance between the circumferential walls of said socket being gradually diminished at points remote from said abutment surfaces to thereby produce a frictional engagement between said wall and the edges of the faces, the circumferential walls of said socket between said teeth being formed on radii of progressively diminishing lengths'at progressively remote points in a counter-clockwise direction viewed from the top from one-cooperating pair .of abutment surfaces to grip. theiedges ofa tool, Of suitabl'fwidth diametrally disposed iii-said socket upon rotation of said tool in thesocket away from, said cooperating i pair a of abutment {surfaces ofsaid'teeth- [3. A screw having a. tool-receiving socket di'- mensi'onedfto receive' an elongated first type tool diametrally positioned t e ei said socket being engagement by said toolrwhenf rotated in one providedjwith'abdtment surfaces.- disposed for direction and with inclined surfaces arranged to frictionally engage said tool when rotated in a screw having a head provided with a socket abutment positioned to be engaged by a flat face of said tool when rotated in one direction whereby movement of said tool is imparted to said screw head, the circumferential walls of said socket being formed on progressively diminishing socket radii to provide a frictional engagement with the edges of said tool when rotated in a reverse direction.

5. The combination with an elongated fiattened tool, of a screw having a socket dimensioned to freely receive said tool in diametral position therein, said socket being shaped to present an abutment in the path of said tool when rotated in one direction from said position and to oppose by frictional resistance the rotation of the tool in theopposite direction from said position whereby a frictional connection between said tool and said screw is established.

6. A screw having a tool receiving socket provided with abutment means. for transmitting turning movements in one direction of a tool in said socket, and with friction means for frictionally locking said tool and screw together upon turning movement of the tool in the opposite direction.

'7. A screw provided with a tool receiving socket, opposite portions of the circumferential walls of said socket being eccentric to the longitudinal axis of the socket.

8. A screw provided with a tool receiving' socket, a portion of the circumferential walls of said socket being disposed eccentrically with respect to the longitudinal axis of said socket.

9. A screw provided with a tool receiving socket, said socket being equipped with spaced apart abutment teeth and having circumferential walls between said teeth formed eccentrically with respect to the longitudinal axis of said socket.

10. A screw provided with a tool receiving socket presenting abutment surfaces for engagement by a tool when said tool is rotated in one direction in said socket and presenting inclined surfaces for frictional engagement by said tool when rotated in the opposite direction in said socket whereby said screw may be frictionally attached to said tool.

11. A screw having a tool receiving socket shaped to provide a tool engaging surface formed on a curve eccentric to the longitudinal axis of 

